Floor scrubbing brush



De.v 1966 R M, BARRY FLOOR SCRUBBING BRUSH Filed April '7, 1965INVENTOR. Foes/er M BAR/vr t/q @9% rroRA/frs FZ5: E

United States Patent O 3,290,713 FLOOR SCRUBBING BRUSH Robert M. Barry,St. Paul, Minn., assignor to Multi-Clean Products Incorporated, St.Paul, Minn., a corporation of Minnesota Filed Apr. 7, 1965, Ser. No.446,270

2 Claims. (Cl. 1S-180) machine base, which encircles and extends overthe top` of the brush. The rotary drive shaft extends. downwardlythrough the center of the shield for axial connection to the brush. Thepurpose of this invention is to provide improvements in this generaltype of brush assembly.

One object of the invention is to provide a floor scrubbing machinehaving a rotary brush disposed for rotation within an annular shield orhood wherein the brush has an equilateral polygonal configuration forease of insertion into and removal from the shield and of mounting padson the brush.

Another object of the invention is to provide a new and improvedconstruction for a rotary floor scrubbing brush which will perform abetter scrubbing action upon a fioor surface and which will have greaterdurability than -a circular brush.

Still another object of the invention is to provide a new and improvedrotary brush for a floor scrubbing machine which brush will cover thesame oor area during rotation as a circular brush but which is sodesigned to have a substantially lighter weight than a circular brush tothus require less power in the machine.

Still another and more specific object of t'he invention is to provide arotary floor scrubbing brush with a construction wherein the bristleshaving the greatest abrasive action upon the floor surface will retaintheir stiffness and toughness just as long as the bristles performing alesser degree of such action.

With these objects in mind the invention broadly comprises a brushhaving an equal sided polygonal-shaped back-board mounted within anannular machine base or shield for rotation upon an upright axis, theunderside of the backboard being covered with downwardly extendingbristles for scrubbing engagement with a oor surface, the bristles onthe radially outermost portions of the back'board being high molecularweight-polymer filaments as distinguished from the remaining bristleswhich are natural fibers.

The above mentioned and still :additional objects of the invention willbe brought to light during the course of the following specification,reference being made to the accompanying drawing, in which:

FIG. 1 is a side elevation of a floor scrubbing machine base embodyingthe subject invention and shown in scrubbing position on a floorsurface.

FIG. 2 is lan inverted plan view of the invention taken on line 2 2 ofFIG. 1.

FIG. 3 is a vertical diametrical section through the base taken on line3 3 of FIG. 2.

Referring now more particularly to the drawing, reference characterswill -be used to denote like parts or structural features in thedifferent views. FIG. l shows a conventional floor scrubbing machinebase designed to be moved over a floor surface F by suitable handlemeans to perform a rotary scrubbing action against the surface as waterand detergent are applied thereto.

Base 10 includes a circular shield 11 having a circular concave top wall12 which peripherally curves into an annular side wall 13 to form adownwardly opening brush chamber 14. An electric motofr 15 is mounted onthe top wall 12 for driving a shaft 16 which extends downwardly andaxially through the wall 12 into chamber 14.

A fiat floor scrubbing brush, denoted generally at 17, is mounted withint-he chamber 14, This brush has a square backboard 18 of rigid materialsuch as wood treated or coated against moisture deterioration. Backboard18 is mounted concentrically within the wall 13 by having its centerconnected to the shaft 16 to be rotational'ly driven thereby. As will benoted by observance of FIG. 2, the corner-to-corner dimension ofbackboard 18 is only slightly less than the diameter of the chamber 14so that there is a close lit of the board within the shield withoutactual engagement therebetween. This leaves four uniform circle segmentspaces or pockets 19 around the backboard between the board sides andthe shield wall 13.

Referring now particularly to FIG. 2, the arrangement and makeup of thebrush bristles will be described. Each corner of the backboard isprovided with a square section of bristles 20` of nylon, These bristlesmay also be formed of polypropylene or any other high molecular weightpolymer filaments. The remaining bristles, denoted at 21, are formed ofbassine or other natural fibers conventionally used in floor brushconstruction. It is preferred that the bristle 20 sections comprise fromtive to fifteen percent of the overall bristle area, with saidpercentage being distributed uniformly to the four corners of the brush.

Bristles 20 have substantially different inherent characteristics thanthe bristles 21. The former have a higher coefficient of friction, agreater tensile strength and a greater resistance to abrasion than thelatter. Moreover, the polymer lafments 20 have a more regular patternand are inert to caustic chemicals, dilute acids and harsh detergents.All of' these characteristics give the bristles 20 substantially greaterwear life than the bristles 21. This is significant as, of course, thebristle sections 20 travel a substantially greater distance duringoperation than do the bristles located near the center of the brush.

It will accordingly be understood that the corner sections 20 willresist taking a set and thus effectively perfonm their scrubbing actionfor a longer period of time than would natural fiber bristles located inthese areas. At the same time the cost of the brush is increased onlyminimally as the more expensive bristles 20 are used in a relativelysmall quantity.

The .square brush will, of course, rotationally cover the same floorarea as a circular brush. However, the square configuration leaving thepockets 19 therearound within the wall 13 allows ready manual grippingof the brush for insertion into or removal from the shield 11. Theprotruding corners of the backboard also facilitate the mounting of apad under the brush, where such is desi-red, with the pad loops hookingover the corners. These advantages are not present where a circularbrush is used,

The power supply demand is another important advantage in this brushover the circular brush fully fitted with natural fibers. Presentconventional household electric power supply greatly limits the size ofa machine of this type that can be used in the home. Accordingly forspeed of polishing, scrubbing or finish removing it is highly desirableto provide Aa brush which will give maximum surface coverage within thepower limits. The square brush provides this advantage. For example, it

is found that a 25 inch full-filled circular brush requires a two h p.motor to drive the brush at 175 revolutions per minute during thedesired operations. On the other hand, where the present |brushconstruction, with a 25 inch `diagonal dimension, is used, a one h.p.motor will adequately drive the brush at the same speed throughout thesame scrubbing and polishing steps.

Still another advantage is the polygonal brush over the circular brushlies in the fact that it has a leading brush edge engaging the floorsurface during rotation to perform a more effective scrubbing action.

The invention accordingly economically and effectively carries out theaforementioned objectives. It is understood that suitable modificationsmay be made in the structure as disclosed, provided such modicationscome within the spirit and scope of the appended claims. Having nowtherefore fully illustrated and described my invention, what I claim tobe new and desire to protect by Letters Patent is:

1. In a floor scrubbing machine, a downwardly opening annular base, a:brush mounted within the base for rotation on the center axis of thebase, said bmsh having a horizontally disposed backboard enclosed Withinthe base with bristles covering the underside of and extendingdownwardly from the back-board beyond the base opening whereby when thebristles are engaged with a floor surface the base will be supportedthereby in spaced relation to the surface, said backboard having thehorizontal configuration of an equilateral polygon with the cornersthereof lying just within the annular wall of the base, and the bristleson the corner areas of the backboard being formed of a material having agreater resistance to abrasion th-an the material forming the remainingbristles in the brush.

2. In a floor scrubbing machine having a downwardly opening annularshield and a brush journaled axially within the shield for rotation onan upright axis, said brush having a square backboard with bristlescovering the underside thereof and extending downwardly therefrom forengagement against a floor surface, the bristles on the corner sectionsof said backboard being formed of material having a greater tensilestrength than the remaining bristles on the backboard.

References Cited by the Examiner UNITED STATES PATENTS 1,206,031 11/1916Ritter et al. 15-180 1,393,532 10/1921 Howard 15-98 1,958,658 5/1934Engberg et al 15-180 2,671,920 3/1954 Finnell 15-180 3,072,944 l/1963Clayton et al. 15-167 3,181,193 5/1965 Nobles et al. l5-180 X 3,186,0196/1965 Hattori l5--l59.1

FOREIGN PATENTS 1,337,633 8/1963 France.

CHARLES A. WILLMUTH, Primary Examiner.

P. FELDMAN, Assistant Examiner.

1. IN A FLOOR SCRUBBING MACHINE, A DOWNWARDLY OPENING ANNULAR BASE, ABRUSH MOUNTED WITHIN THE BASE FOR ROTATION ON THE CENTER AXIS OF THEBASE, SAID BRUSH HAVING A HORIZONTALLY DISPOSED BACKBOARD ENCLOSEDWITHIN THE BASE WITH BRISTLES COVERING THE UNDERSIDE OF AND EXTENDINGDOWNWARDLY FROM THE BACKBOARD BEYOND THE BASE OPENING WHEREBY WHEN THEBRISTLES ARE ENGAGED WITH A FLOOR SURFACE THE BASE WILL BE SUPPORTEDTHEREBY IN SPACED RELATION TO THE SURFACE, SAID BACKBOARD HAVING THEHORIZONTAL CONFIGURATION OF AN EQUILATERAL POLYGON WITH THE CORNERSTHEREOF LYING JUST WITHIN THE ANNULAR WALL OF THE BASE, AND THE BRISTLESON THE CORNER AREAS OF THE BACKBOARD BEING FORMED OF A MATERIAL HAVING AGREATER RESISTANCE TO ABRASION THAN THE MATERIAL FORMING THE REMAININGBRISTLES IN THE BRUSH.